Starting in 1961, Nelson had a decades-long stage career, performing, directing and producing, primarily in New York. She was a featured performer on Broadway in 1970 in the musical Purlie. In 1975, Nelson directed the play La Femme Noire at The Public Theater. Her film career began at age 39 with a small part in 1977's An Unmarried Woman, and continued for the next several decades with roles in movies and television.